crypto: hash - Remove support for cloning hash tfms

crypto: hash - Remove support for cloning hash tfms

Hash transformation cloning no longer has a user, and there's a good
chance no new one will appear because the library API solves the problem
in a much simpler and more efficient way.  Remove support for it.

Note that no tests need to be removed, as this feature had no tests.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://patch.msgid.link/20260522053028.91165-2-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>